Method and apparatus for treating strings or strands



Aug. 16, 1932 H. wlLLsHAW ET AL, 1,871,766

METHOD AND APPARATUS FR TREATING STRINGS OR STRANDS Filed July s1, 19282 sheets-sheet 1 Nm. m. A Q K x bx. S Ww Qn rf/ l/// 1 lll/lill l/ll /11/ ll lll/l l l lll/lll: l /l/ lZ/l//l/lll/ll/ A118216, l932 H. wlLLsHAwET AL 1,871,765

METHOD AND APPARATUS FOR TREATING STRINGS QR `STRANDS 'Filed July 31,1928 nbawtoza HARRY l/s//LLs/m w, 'YoA/EY/VEv/LE @oom/m mvo PatentedAug. 16, 1932 p i UNITED STATES HARRrwILLsHAw, or' WYLDE GREEN,sYDNEYNEVILLE GooDHALL,- oEfMARsTON GREEN, AND oHARLEs EoLLIss, or BIRMINGHAM,ENGLAND, AssIGNoRs To DUNLOP RUBBER COMPANY LrMITED, or ERDINGTON,BIRMINGHAM, ENGLAND, A :BRITISH` CORPORATION Y METHOD AND ArTARATUs roRTREATING STRINGS oR sTRANDs thereby developed is advantageously utilizedtov actuate devices which maintain a continual longitudinal pull uponthe strings, the tension so imparted comprising an essential featureofthe treatment.

Another object is to construct such'apparatus so that thestrings orstrands are continuously tensioned, irrespective of the degree to whichthey yield treatment.

A further object is in constructing such apparatus so that the tensionimparted to the longitudinally during the strings or strands isproportioned to the heat to which theyV are subjected.

` The strings or strands to. which this invention relates are generallyreferred to in the ltrade as gut strings, not'` so much on account 3uof'their constituents, but more on account of their application. Suchstrings have a markedV application for stringingtennis rackets. Theinventionis particularly applicavble to strings composed atleast in partof either rubber, gutta percha, or similarvege table resins. A A

In orderthat this invention may be clearly understood,'reference shouldbe made to the accompanying drawings wherein- Fig. l is a part sectionalside elevation of the apparatus; Y Fig. 2 is a plan viewof Fig. 1;

Figi?) is a cross-sectional view on line 3-3 s of Fig. 1;

Fig. l is a part sectional view on an enlarged scale of theY yieldinghook member;

within the container. v f .In aconvenient embodiment of Ithe appara-`thereon lengths of the strings orv n Application filed July 31, 1928,Serial No. 296,588, and in Great Britain August 4, 1927.V

tus according to the invention, we employ essentially a heating chamber1 having a door PATEN orales' or closure member z2 at one end, and beingconclosed. Y Y

Capable of Ventering the heating chamber is a frame or carriage member 3for receiving strands 4;

structed to make a gas-tight vjuncture'when to undergo the treatment.v

The frame or carriage may be rectangular in shane land comprises two endmembers 5--6 which correspond with the shorter sides of the rectangleand two side members cor# responding with the remaining longer sides ynipulation of the framewhen being placed into or removed from theheating chamber. Providedrupon the end members of the frame or carriage3 and lsubstantially vin alignment with one another are hooks orV otherretaining devices 9-10 for receiving the ends of the gut or otherstrings or strands 4.

The hooks or other devices 9 at the one struction and constitute animportant feature of the invention. Each of these latter` hooks 10comprises essentially a stem portion 11 having a hook at one endwhile-on the other end is a piston 12 of suitable proportions. Thispiston is adapted to work within an elongated cylinder 13 which issecured4 in a suitable manner to a chest or other hollow member 14: atthe end 6 of the frame. l

Along the stem portion of this combined hook and piston member is aseries of ratchet teeth 15 and coacting with those teeth is a gravityactuating pawl or detent 16 mounted upon a spindle 17 fixed in relationtothe cylinder.

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2.9; structing this apparatus Vaccording to this in-v Y the atmosphere.Sui-table provisionis made 'f5 to ensure that the joint between theextend- In order to support the cylinder 13 its eX- tended end 18 towhich the pawl 16 is secured, is received within an aperture in a platemember 19upstanding from and mounted upon the frame member.

Further, to ensure the ease of movement of the stem along the cylinder,it may be adaptedto rest upon a roller or other member 20`mouiited at2'1atthe open end of the entension 17.y The function of this combined hookand piston is asfollows The piston is forced.v along the cylinder in thedirection' towards the end of the frame" or carriage to which it issecured in consequence of pressure acting upon it and as the pistontraverses the cylinder, itv draws the stem and hook with it causing thedistance between the two hooks to increase.

Another feature of importance in con vention refers 'to the cylindermembers. `In order that the pistons may traverse along the, cylinders itis necessary to remove and insu# late the pressure from theirinoperative faces.y

To accomplish this we cause the cylinders 1.3 to communicate with a.hollow chamber` 14 mounted at the end 6 of theframe or carriage.

Connected to this hollow chamber 14 anv `extending pipemember 22 whichis capable of passing through an aperture23 in the wall `of the heatingchamber-thereby placing this hollow chamber-in direct communication withing pipe member and the .aperture inthe heatingchamber is steam orgas-tight and ina construction adopted we have. provided a somewhatconical shaped facing 24 near the end4 of the extending pipe vmember 22and` whichis adapted to co-operate with a corresponding conical seating25 around the aper:

ture within the heating chamber. The corresponding-.seating 25 isprovided within Va ring 26 afndis. mounted to permit of radial dis- Yplacement, so that it will readily align itselfl with the pipe member,the ring further contacting with a packing member 27 provided within thefacing of one ofthe members of .its housing.-

In operation,` the extending pipe member 22 is. passed through theaperturein the heatingchaniber until the respective facil-lgs andseatings engage, the pressure within the chamber maintains them inengagement,V but in zorder to ensure of their more intimate engagementwe' apply a nut-like. member 28` upon al screw/threaded portion 29providedat the remote end 30 of the extendinggmember 22, l

If desired a buffer or eXtensible member 31 .acted upon -by-a spring 32may be provided atthe end 5 of the. frame 3.

In operatiom the strings or strands are rst attached to the hooks orother retaining:

members 9-10. The frame or carriage is then placed into the heatingchamber, after which the door or closure member'2 is tight.

ly secured and the nut-like member 28 placed in position on the extendedpipe.

VWe now cause heat and pressure to develop within the heating chamber byforcing there-` into steam, or other fluid, through an aper# ture'as 33in Fig. l or-by any other'nieans The heat developed bythe steamor otherheated iiuid acts upon the strings of rubber or gutta percha and similarvegetable resins in a manner generally known as vulcanizing causing thecharacteristics of the strings orstraiids to somewhat alter, while thepressure operates the tensioning devices, it being appreciated that adierence inpressure or` heat occasions difi'erentresultsfThus itis clearthat the strings are simultaneously vul-r` canized under tensionandpressure.v f

'Ihe term vulcanizing7 hereinbefore men,-4 -tioned refers generally tothe treatment which may be applied to anytypes of strings and strandsthe characters of which Ialter when subjected to heat and does notsolely refer to strings or strandswherein rubber is one of thecomponents as the yterm may sug-' Gest. y y, When the requiredpressure-and'heat have been produced within the heating chamber,it

will be foundthat the pistons have ybeen forced into the cylinders andretained against return movement by( the gravity actuated pawlsengagingwith the ratchet teeth'on the i stems of the combined pistons and hooks,reference should be made to Fig. 2, where one of the hooks 10 is shownin the position it.

assumes at the commencement of thevtre'atment, while theoth'er hook 10is shown with the pressureV acting upon it7 and imposing a tension uponthe 'strings-as atthe finish of the treatment. 'Upongthetreatment havingvbeen completed, the strings or strands caribe removed from theapparatus by releasing the pawl from engagementr with the ratchet teeth.From the foregoing descriptionr it will'be observed that the gut strings'or the like have."

been described as being treated in a single length and having eachoftheir endsattached toa retaining device, but we may if-desired treatthem in any other manner, such for instance as in doubled lengths asshown in- Fig.

2T where we provide two retaining hooks at to greater or lessereXtennfthere isa pro rata` variation in the pressure within thechamber..-

This conditionis effected in. one instance by over the combined pistonvthe characteristics of the iiuid, as for instance with steam,alternatively, and when other fluid is used for instance heatedv air, athermionic or other valve may be used to control the admittance of thefluid according to its heat, and thereby govern the pressure within thechamber.

Also it will readily be appreciated that the Y frame or carriage may beconstructed to receive any number of strings, see Fig. 3, where a numberof apertures 34 are shown for receiving the hooks 9. According to theforegoing descriptiomthe hooks 9 are described as being of a rigid andunyielding nature, but it should be understood that the rigidity isrequired only in the longitudinal direction, but for convenience theapertures 34 are of keyhole formation, permitting the hooks of lateraldisplacement to allow them to be readily connected to` or disconnectedfrom the frame, the enlarged part 35 of the hooks retaining the hooks inthe narrow part of the aperture 34.

It will be appreciated that constructional details may be modifiedwithout departing from the objects of the invention.

The strings or strands referred to usually comprise a stranded corecoated with gutta percha or similar vegetable resins. lSuchV strandedcore may be'of the usual string-like iiber or in some cases it is madeof one or more metallic wire strands.

Having now particularly described and ascertained the nature of the saidinvention, and in what manner the same is to be performed, we declarethat what we claim is l. The method of treating strings of vulcanizablematerial of the kind described, which comprises subjecting Vsaid stringsto fluid under pressure at a vulcanizing temperature and imposing alongitudinal tension upon said strings, said tension being a function ofthe pressure of said iuid.

2. The method of treating strings of vulcanizable material of the typedescribed, which comprises subjecting said strings to fluid underpressure at a vulcanizing temperature and imposing a longitudinaltension upon said strings, said tension being directly proportional tothe pressure of said fluid.

3. The method of treating strings of vulcanizable material of the typedescribed, which comprises subjecting said strings to a fluid underpressure at a vulcanizing temperature, and continuously and constantlytensioning said strings during vulcanization irrespective of the lengthof stretch occurring in them, and with a tension proportional to thepressure of said liuid.

4. Apparatus for treating strings of the type described, which comprisesa fluid-tight chamber, a frame having retaining devices for receivingand carrying said strings, said retaining devices being movable to andfrom each other, and means for moving said retaining devices toyincrease the distance between them and to impose a. ,longitudinaltension upon; strings supportedr between said devices.

x5.. Apparatus of the type described,whi'ch comprises a pairof retainingdevices for supporting-strings extending therebetween and comprises apair of retaining devices for supporting strings extending there betweenand attached thereto, means for separating said devices from eachotherzunder pressure toV tension said strings, means for Vretaining saiddevices in'l separated positions against vthe, tensioning action ofsaid-strings,"and`means for supplying fluid under `pressure to saidstrings.`

7 Apparatus ,of the Vtype described, `which' comprises a-frame, stringsupportingl andi retaining devices, relatively movable on said'V frameto impose alongitudinal tension: upon strings; v supported between said.devices,

means `for movingsaid devices yfrom each other,means for-preventing thereturn move-4 ment of said receiving devices, and means for supplyingfluid Vunderw'pressure ,tor said strings. f 'Y v l c 8. Apparatus of thetypedescribed, which comprises relatively movable stringi retainingdevices, a cylinder, a piston in said 'cylinder and connected tok one ofsaid movable devices, means for imparting -a difference of pressur-e tolopposite sides of said piston ,to

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move said devices apart relatively to each other, and means -Aforsupplyingfluid under pressure t0 saidstrings.

9. `Apparatus of thetype described, which f comprises relativelymovablestriiig retaining-devices, a cylinder, piston inA said cylinderand `connected tolone-of'said movable devices, means forimparting adiiierence of pressure to opposite sides of said piston to move saiddevices apart relatively to each other, a ratchet and pawl means forpreventing return movement of said movable retaining means, and meansfor supplying' fluid under pressure to said strings.

10. Apparatus according to claim 8, wherein the cylinder communicateswith the atmosphere.

izo

l1. Apparatus of the type described, which' comprisesa Huid pressurechamber, means in fixed position in said chamber to engage a string tobe stretched, movable-*means in said chamber for engaging said string, acylinder in said chamber communicating with the atmosphere, and a.piston in said cylinder tween the atmosphere and the interior of'y 1' Asaid chamber,A and means for supplying.

heat-ed fluid underpressure'to saidchamber. 12. Apparatusk for treatingstringsof the kind specied5 comprising -aA Huid tight Vchamber withiiuid admitting orice and.

with a displaceable end,v and having rails at its floor in combinationwith a frame or car-V riage mounted on said rails and capable` of beingvrmovedinto or from said chamber, the

said frame or carriage having. string retain-v ing devices some offwhichcan move under the pressure of. the iiuid to kimpose a longi- N tudinal`tension uponsaid strings, vwhereinV the cylinders for receiving themoving devices communicate with f the atmosphere through a hollow memberextending through thewall of the container `and a fluid tight p y juncture'between said hollow extending mem- Y 20' ber and said container.1 n

13. In apparatus according to claim 12, a

Y fluid tight juncture comprising a male member having a conicallyshaped'surface receivedwithin a correspondingly shaped float-l ingfemale member, substantially as described. v

14. In apparatus Huid tight juncture comprising" a male member having aVconically shaped surface received within a correspondingly shapedfemale member, the*` union between them being occasioned by the pressureof the fluid within the containenf l 1 15. In apparatusaccording toclaim 12 wherein the union between the male andv female members isassured by a nut substantially as described.

V16. In apparatus according to claim 12 u -wherein Vretaining devcesaredispl'aceable 4:0VA

laterally and received withinl a keyhole shaped aperture substantiallyas described.4

In witness whereof, we have f hereunto signed our names.` f f f Y HARRYVVIl'JLSI-IAI;V lSYDNEY NEVILLE GOODHALL.' GHARLESIOLLISS. A Y i 7according toclaim l152,' a i

